Sudden death syndrome is often sparked by an irregular heartbeat.
The Sun (2012)
DRINKING too much cola can cause fainting and an irregular heartbeat, a study found.
The Sun (2013)
An irregular heartbeat was initially diagnosed, but cleared up of its own accord.
Times, Sunday Times (2015)
The conducting tissue may also be affected, causing irregular heartbeat.
MacIntyre, Anne M. E. Post-Viral Fatigue Syndrome - How To Live With It (1989)
An irregular heartbeat or a blood clot are suspected by the coroner.
The Sun (2016)